rfb_13199_for_info_only_9-groundwater_dewatering_study.pdf

Groundwater Dewatering Study Cole Grade Road Bridge Over Keys Creek Project

Valley Center, San Diego County, California Oracle No. 1003046

County of San Diego – DPW Materials Lab 5252 Kearny Villa Way, San Diego, California 92123

June 21, 2023 | Project No. 108611016

Geotechnical | Environmental | Construction Inspection & Testing | Forensic Engineering & Expert Witness

Geophysics | Engineering Geology | Laboratory Testing | Industrial Hygiene | Occupational Safety | Air Quality | GIS

Courtney Brooks Principal Hydrogeologist

Stephan A. Beck, PG, CHG Manager, Environmental Sciences Division

Groundwater Dewatering Study Cole Grade Road Bridge Over Keys Creek Project Valley Center, San Diego County, California Oracle No. 1003046

E. David Gasaway, P.E., Senior Civil Engineer County of San Diego – DPW Materials Lab 5252 Kearny Villa Way, San Diego, California 92123

June 21, 2023 | Project No. 108611016

5710 Ruffin Road | San Diego, California 92123 | p. 858.576.1000 | www.ninyoandmoore.com

CJB/SB/gah/mp http://www.ninyoandmoore.com/

Ninyo & Moore | Cole Grade Road Bridge Project Over Keys Creek, San Diego County, California | 108611016 | June 21, 2023 i

CONTENTS

1 INTRODUCTION 1

2 PROJECT DESCRIPTION 1

3 AQUIFER TEST WELL INSTALLATION 1

4 GRAIN SIZE ANALYSIS 2

5 GROUNDWATER SAMPLING AND ANALYSIS 2

5.1 Reasonable Potential Analysis 3

5.2 Total Maximum Daily Loads 3

6 AQUIFER HYDRAULIC ANALYSIS 4

7 GROUNDWATER MODEL DESIGN AND OUTPUT 5

8 CONCLUSION 6

9 LIMITATIONS 6

10 REFERENCES 8

TABLES

1 – Dewatering Modeling Parameters 4

2 – Dewatering Modeling Input / Output 5

FIGURES

1 – Site Location 2 – Site Plan

APPENDICES

A – DEHQ Monitoring Well Construction Permit B – Boring Logs and Well Construction Diagram C – Well Development Logs D – Waste Manifest E – Grain Size Analysis F – Laboratory Analytical Reports G – Reasonable Potential Analysis H – Dewatering Analysis Model Results I – Well Test Data and Hydraulic Conductivity Model Results

Ninyo & Moore | Cole Grade Road Bridge Project Over Keys Creek, San Diego County, California | 108611016 | June 21, 2023 1

1 INTRODUCTION

Ninyo & Moore was retained by the County of San Diego (County), Department of Public

Works (DPW) to perform a Groundwater Dewatering Study (GDS) for the Cole Grade Road

Bridge Over Keys Creek Project (Project). The Project is located in the unincorporated community of Valley Center in the County of San Diego on Cole Grade Road where it crosses

Keys Creek between Cool Valley Ranch Road and Cool Valley Road (Figure 1). This

Groundwater Dewatering Study consisted of the installation and development of three monitoring wells, groundwater sampling and analysis, aquifer testing, and dewatering calculations.

2 PROJECT DESCRIPTION

The Project will provide a new bridge crossing of Cole Grade Road over Keys Creek intended to meet current roadway and bridge standards and accommodate the planned road widening. The

County anticipates temporary dewatering for installation of articulated concrete block (ACB) for scour protection in Keys Creek channel.

3 AQUIFER TEST WELL INSTALLATION

Drilling, logging, and well installation activities were conducted on December 7 and 8, 2021 by

ABC Liovin Drilling, Inc., under the oversight of a Ninyo & Moore California-registered

Professional Geologist, in accordance with the County of San Diego, Department of

Environmental Health and Quality (DEHQ) monitoring well construction permit (Appendix A).

Two 8-inch diameter borings and one 10-inch diameter boring were drilled to 30 feet below ground surface (bgs) within the footprint of the proposed bridge structure, using a limited access drill rig equipped with hollow-stem augers (Figure 2). Soil samples were collected from each boring using a split-spoon sampler for lithologic logging. Groundwater was measured at 12 to

13 feet bgs during drilling. Boring logs are included in Appendix B.

The three borings were converted to groundwater monitoring wells (one 4-inch diameter test well [TW] and two 2-inch diameter observation wells [OW]), which were constructed of

Schedule 40, 0.020-inch slotted PVC casing from approximately 30 to 10 feet bgs and

Schedule 40 PVC solid casing from 10 feet bgs to the surface. After installation of the casing, a filter pack consisting of #3 sand was placed in the annulus of each borehole from 30 to 8 feet bgs. The filter pack was measured during installation to monitor the depth and potential bridging that may occur between the well casing and the borehole wall. Following placement of the filter pack, the wells were surged and additional filter pack was added, as necessary. A bentonite seal of hydrated medium bentonite chips was placed in the annulus above the filter pack from 8 to

Ninyo & Moore | Cole Grade Road Bridge Project Over Keys Creek, San Diego County, California | 108611016 | June 21, 2023 2

5 feet bgs, followed by bentonite / cement grout from 5 to 3 feet. The wells were completed at the surface with 12-inch diameter, traffic-rated well boxes placed in concrete from 3 feet bgs to ground surface. The monitoring well construction diagrams are presented in Appendix B.

The wells were developed on December 10, 2021 using surge, bail, and pump techniques. Field measurements (i.e., static/pumping/recovery groundwater depths, pH, electrical conductivity, oxidation-reduction potential, temperature, dissolved oxygen, and turbidity) were taken and recorded on well development logs (Appendix C). The purpose of well development is to promote hydraulic connection with the surrounding aquifer by removing fine-grained material that becomes smeared along the borehole wall and entrained in the filter pack.

Soil cuttings were placed in properly labeled 55-gallon drums, sampled, and disposed at an appropriately permitted offsite facility. The waste manifest is provided as Appendix D. Purge water generated during well development was placed into Department of

Transportation (DOT)-compliant 55-gallon drums, labeled with pertinent information, and temporarily stored and reused onsite.

4 GRAIN SIZE ANALYSIS

Soil samples collected from 30 feet to 10 feet bgs from the test well boring (screened interval) were submitted to Ninyo & Moore’s in-house soil testing laboratory for sieve and hydrometry analyses (collectively referred to as gradation testing). The resulting analysis indicated poorly graded silty sand. The gradation test results are included in Appendix E.

5 GROUNDWATER SAMPLING AND ANALYSIS

On February 1 and 2, and March 2, 2022, Ninyo & Moore personnel collected grab groundwater samples from the TW and surface water samples from Keys Creek. The samples were collected using a new disposable bailer and placed into laboratory-supplied containers. Sample containers for total petroleum hydrocarbon (TPH) as gasoline and volatile organic compounds (VOCs) analyses were filled without the presence of headspace. The sample containers were labeled with pertinent information (e.g., sample identification, date, and time, samplers’ initials, and analyses required), placed in zip-lock plastic bags, which were stored in a cooler with ice, and transferred under chain-of-custody procedures to Eurofins Calscience

(Eurofins) and EnviroMatrix Analytical, Inc., state-certified laboratories for analytical testing. The laboratory analytical reports are provided in Attachment F.

Ninyo & Moore | Cole Grade Road Bridge Project Over Keys Creek, San Diego County, California | 108611016 | June 21, 2023 3

5.1 Reasonable Potential Analysis

The tabulated results of the Reasonable Potential Analysis (RPA) are included as

Appendix G, Tables G-1 to G-3. Parameters with presumptive reasonable potential are listed in Table G-1. Performing an RPA is one of the requirements for obtaining a National

Pollutant Discharge Elimination System (NPDES) construction dewatering permit in accordance with San Diego Regional Water Quality Control Board (RWQCB) Order R9-

2015-0013, NPDES NO. CAG919003, General Waste Discharge Requirements for

Groundwater Extraction Discharges to Surface Waters within the San Diego Region. The purpose of the NPDES permit is to regulate the discharge of waste (e.g., contaminated groundwater generated by construction dewatering) to surface water.

The water quality objective/criteria trigger values and analytical results for metals listed on

Table G-2 are based on the total hardness of the receiving water, Keys Creek

(1,110 milligrams per liter). The results for cadmium, copper, lead, nickel, silver, and zinc did not exceed the water quality objective/criteria trigger values and therefore are not considered to have a reasonable potential to cause, or contribute to an excursion above the

State water quality standard.

Table G-3 provides the RPA for discharges to freshwater receiving waters without a municipal designation. The following groundwater parameters exceeded the RWQCB Order trigger values: total nitrogen, total recoverable iron, total recoverable manganese, total recoverable selenium, and chlorinated dibenzodioxins and dibenzofurans isomers (TCDD

Equivalents). The exceedances indicate there is a potential for these parameters to cause or contribute to an excursion above State or Federal water quality criteria. Therefore, based on this RPA, groundwater generated by construction dewatering would require appropriate treatment to reduce contaminant concentrations below RWQCB Order trigger values before being discharged to surface water. Note that the four TCDD Equivalents detected in the sample were “J” flagged, which indicates that the result is less than the reporting limit, but greater than or equal to the method detection limit, and the concentration is an approximate value.

5.2 Total Maximum Daily Loads

Total Maximum Daily Loads listed in RWQCB Order R9-2015-0013 were reviewed and were not found for Keys Creek.

Ninyo & Moore | Cole Grade Road Bridge Project Over Keys Creek, San Diego County, California | 108611016 | June 21, 2023 4

6 AQUIFER HYDRAULIC ANALYSIS

Based on the borehole lithologic logs prepared during the drilling of the borings for the TW and OWs and materials laboratory gradation test results (Appendices A and E), the saturated soil at the site is primarily comprised of poorly graded silty sand to weathered granodiorite. Additionally, Ninyo & Moore performed aquifer testing of the wells, the output of which was analyzed using the hydrogeologic platform AQTESOLV (Appendix I). The

AQTESOLV calculated estimated hydraulic conductivity values ranged from 1 foot per day (ft/d) to 1.3 ft/d; in this case, hydraulic conductivity is essentially a measure of how easily water can flow through soil or rock, a higher value indicates a higher potential flow rate. For this study, Ninyo & Moore selected the higher, more conservative, hydraulic conductivity estimate for use in the groundwater model to estimate the approximate flow rates that could be expected to achieve project dewatering objectives and be used in the preparation and submittal of the Notice of Intent (NOI) for an RWQCB Order R9-2015-0013

NPDES construction dewatering permit. Table 1 below presents the model design data derived from field measurement, review of the 100% plan submittal, and input from the

County.

Table 1 – Dewatering Modeling Parameters Parameter Description Model Input

Site Elevation* 1434' AMSL

Depth to Groundwater** 12'

Groundwater Elevation 1422' AMSL

Base of Articulated Concrete Block Elevation*** 1420' AMSL

Target Dewatering Elevation*** 1418' AMSL

Target Dewatering Drawdown 4'

Calculated Hydraulic Conductivity 1.3 ft/day

Notes:

* From Foundation Report (Ninyo & Moore, 2015).

** Measured in Test Well, February 1, 2022, prior to Step Testing. Subject to change based on actual conditions during construction.

*** Provided by County in an email dated June 15, 2022 and on 100% construction plans, dated May 24, 2022.

AMSL – above mean sea level (NAVD 88).

All elevations/depths are approximate and rounded to the nearest foot.

Ninyo & Moore | Cole Grade Road Bridge Project Over Keys Creek, San Diego County, California | 108611016 | June 21, 2023 5

7 GROUNDWATER MODEL DESIGN AND OUTPUT

For the purpose of this study, a target dewatering elevation of approximately 2 feet below the base of the ACB elevation (to be installed for scour protection) was provided by the County as the dewatering target for the site. The groundwater model processing platform, Groundwater

Vistas, was utilized to create groundwater simulations utilizing the Modflow method (2007).

Computerized finite difference groundwater models were set out on a grid with uniform 10 feet row and column spacing over an area 8,000 feet wide by 4,000 feet long centered between the two points where Cole Grade Road crosses over Keys Creek. The model assumes that homogeneous and isotropic aquifer conditions exist horizontally across the grid and that Keys

Creek will be flowing at the time of construction.

Based on the 100% plans and communications with the County, bridge construction (i.e., ACB installation) is anticipated to require dewatering in two stages to maintain traffic flow on

Cole Grade Road with an ACB footprint of approximately 6,000 square feet (sf) for Stage 1 and

8,520 sf for Stage 2, Figure 2. Therefore, the model was conservatively designed to estimate the approximate number, configuration, and combined flow rate of wells expected to dewater for each stage of ACB installation to the target dewatering elevation. The model was run until steady-state groundwater conditions were achieved (i.e., groundwater recharge and construction dewatering discharge rates are essentially equal). Model results are provided in

Appendix H.

Table 2 – Dewatering Modeling Input / Output Parameter Description Model Input / Output

Articulated Concrete Block Installation Stage 1 – 6,000 sf; Stage 2 – 8,520 sf

Estimated Number of Wells / Extraction Points per Stage 2

Estimated Combined Flow Rate (2 wells) 12 gallons per minute

Note:

The number of wells and flow rate are based on the premise that construction dewatering will be performed in two stages of ACB installation on the west and east sides of Cole Grade Road (Stage 1 and Stage 2, respectively; Figure 2).

The transient model predicts 2 wells with an average flow rate of approximately 6 gpm per well with well / extraction point spacing of approximately 100 feet and approximately 3 to 5 days to reach the anticipated steady state (i.e., equilibrium) target dewatering elevation. Groundwater model data are included in Appendix H.

Ninyo & Moore | Cole Grade Road Bridge Project Over Keys Creek, San Diego County, California | 108611016 | June 21, 2023 6

However, the actual dewatering rates and time it will take to reach the anticipated dewatering elevation and achieve a firm excavation base to accommodate ACB installation will be significantly influenced by the dewatering system design, well construction/development/efficiency, extraction pump size and efficiency, associated discharge rates and duration, actual saturated thickness of the aquifer and flow conditions at the time of construction, and variations based on seasonal conditions

(e.g., actual flow in Keys Creek, precipitation, irrigation schedules, and soil moisture/saturation).

Additionally, the construction means, methods, sequencing, and other conditions will be factors that influence actual groundwater dewatering rates and durations. The dewatering contractor should therefore plan accordingly to avoid unnecessary delays.

8 CONCLUSION

The results of this groundwater dewatering study indicate that an estimated average combined flow rate of 12 gpm (e.g., 2 wells pumping at 6 gpm each) per dewatering stage is anticipated to achieve the project dewatering goals for each stage of articulated concrete block installation.

This groundwater simulation presents a conservative pumping scenario. It does not consider the possible use of shoring/pilings and/or a coffer dam and ancillary pumps to divert surface water from Keys Creek during construction. If these methods are employed, a lower combined flow rate may achieve the anticipated dewatering target elevation.

Based on the results of the RPA, the exceedances of total nitrogen, total recoverable iron, total recoverable manganese, total recoverable selenium, and TCDD Equivalents indicate there is a potential for these parameters to cause or contribute to an excursion above State or Federal water quality criteria and water treatment and/or discharge limitations may be required by the

RWQCB for issuance of an NPDES permit.

9 LIMITATIONS

The environmental services described in this report have been conducted in general accordance with current regulatory guidelines, and the standard-of-care exercised by environmental consultants performing similar work in the project area. No warranty, expressed or implied, is made regarding the professional opinions presented in this report. Variations in site conditions may exist and conditions not observed or described in this report may be encountered during subsequent activities. Please also note that this study did not include an evaluation of geotechnical conditions or potential geologic hazards.

Ninyo & Moore | Cole Grade Road Bridge Project Over Keys Creek, San Diego County, California | 108611016 | June 21, 2023 7

Ninyo & Moore's opinions and recommendations regarding environmental conditions, as presented in this report, are based on limited subsurface assessment and chemical analysis.

Further assessment of potential adverse environmental impacts from past on-site and/or nearby use of hazardous materials may be accomplished by a more comprehensive assessment. The samples collected and used for testing, and the observations made, are believed to be representative of the area(s) evaluated; however, conditions can vary significantly between sampling locations. Variations in soil and/or groundwater conditions will exist beyond the points explored in this evaluation.

The environmental interpretations and opinions contained in this report are based on the results of laboratory tests and analyses intended to detect the presence and concentration of specific chemical or physical constituents in samples collected from the subject site. The testing and analyses have been conducted by an independent laboratory which is certified by the State of

California to conduct such tests. Ninyo & Moore has no involvement in, or control over, such testing and analysis. Ninyo & Moore, therefore, disclaims responsibility for any inaccuracy in such laboratory results.

Our conclusions, recommendations, and opinions are based on an analysis of the observed site conditions. It should be understood that the conditions of a site could change with time as a result of natural processes or the activities of man at the subject site or nearby sites. In addition, changes to the applicable laws, regulations, codes, and standards of practice may occur due to government action or the broadening of knowledge. The findings of this report may, therefore, be invalidated over time, in part or in whole, by changes over which

Ninyo & Moore has no control.

This document is intended to be used only in its entirety. No portion of the document, by itself, is designed to completely represent any aspect of the project described herein. Ninyo & Moore should be contacted if the reader requires any additional information, or has questions regarding content, interpretations presented, or completeness of this document.

This report is intended exclusively for use by the client. Any use or reuse of the findings, conclusions, and/or recommendations of this report by parties other than the client is undertaken at said parties’ sole risk.

Ninyo & Moore | Cole Grade Road Bridge Project Over Keys Creek, San Diego County, California | 108611016 | June 21, 2023 8

10 REFERENCES

California Regional Water Quality Control Board, 2015, Order R9-2015-0013, NPDES No. CAG919003, General Waste Discharge Requirements for Groundwater Extraction Discharges to Surface Waters within the San Diego Region: adopted June 24.

County of San Diego, 2021, 90% Submittal - Plans for Cole Grade Road Bridge Over Keys Creek: dated November 6, 2020.

Ninyo & Moore | Cole Grade Road Bridge Project Over Keys Creek, San Diego County, California | 108611016 | June 21, 2023 9

Waste Manifest

Appendix A

Photographic Documentation

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Ninyo & Moore | Cole Grade Road Bridge Project Over Keys Creek, San Diego County, California | 108611016 | June 21, 2023 10

APPENDIX A

DEHQ Monitoring Well Construction Permit

COUNTY OF SAN DIEGO

DEPARTMENT OF ENVIRONMENTAL HEALTH & QUALITY

LAND AND WATER QUALITY DIVISION

MONITORING WELL PROGRAM

MONITORING WELL CONSTRUCTION PERMIT

SITE NAME: COLE GRADE RD BRIDGE PROJECT OVER KEYS CREEK

SITE ADDRESS: 14215 COOL VALLEY RANCH RD, VALLEY CENTER 92082

PERMIT FOR: CONSTRUCTION OF GROUNDWATER MONITORING WELLS (3)

PERMIT APPROVAL DATE: 10/28/2021

PERMIT EXPIRES ON: 2/28/2022

RESPONSIBLE PARTY: COUNTY OF SAN DIEGO-DPW (E. DAVID GASAWAY)

PERMIT TERMS:

1. Wells must have a minimum 3-foot concrete surface seal. The surface seal shall consist of concrete able to withstand the maximum anticipated load without cracking or deteriorating. The concrete should meet Class A specifications of a minimum 4000-pound compressive strength. Bentonite slurries are not an acceptable annular sealing material in the unsaturated zone.

2. All water and soil resulting from the activities covered by this permit must be managed, stored and disposed of as specified in the SAM Manual in Section 5, II, D-4. In addition, drill cuttings must be properly handled and disposed in compliance with the Stormwater Best Management Practices of the local jurisdiction.

3. Within 60 days of completing work, submit a well construction report, including all well and/or boring logs and laboratory data to the Well Permit Desk. This report must include all items required by the SAM Manual, Section 5, Pages 6 & 7.

4. This office must be given 24-hour notice of any drilling activity on this site and advanced notification of drilling cancellation. Please contact the Well Permit Desk at (858) 505-6688.

NOTE: This permit does not constitute approval of a work plan as defined in

Section 2722 of Article 11 of C.C.R., Title 23. Work plans are required for all unauthorized release investigations in San Diego County.

APPROVED BY: DATE: 10/28/2021

JON SENAHA

PERMIT # LMWP-005262

A.P.N. #: 133-202-06-00

EST #: N/A

S:\LWQ\WELL PROGRAM\Monitoring Wells\Applications (Rev. 7-2019) Page 1 of 3 County of San Diego Department of Environmental Health

PERMIT APPLICATION

GROUNDWATER

AND VADOSE MONITORING WELLS

AND EXPLORATORY OR TEST BORINGS

A. RESPONSIBLE PARTY County of San Diego DPW E-mail Edgar.Gasaway@sdcounty.ca.gov

(The person, persons, or company responsible for the construction, maintenance, and destruction of the proposed borings and/or wells.)

Mailing Address 5510 Overland Avenue, Suite 410 City San Diego State CA Zip 92123

Contact Person E. David Gasaway Phone 858-560-2125 Ext.

B. SITE ASSESSMENT PROJECT NUMBER – IF APPLICABLE # N/A

C. CONSULTING FIRM Ninyo & Moore Mailing Address 5710 Ruffin Road City San Diego State CA Zip 92123

Registered Professional Stephan Beck Phone 858-576-1000 Registration #4375 (PG)

E-mail sbeck@ninyoandmoore.com

Contact Person Adrian Olivares Phone 858-576-1000 Ext 11257 Email aolivares@ninyoandmoore.com

D. DRILLING COMPANY ABC Liovin Drilling C57# 422904 Contact Name Rick Hastings E-mail rick@abcdrilling.com

Mailing Address 1180 East Burnett Street City Signal Hill State CA Zip 90755

Phone 562-981-8575 Ext. 719

E. CONSTRUCTION INFORMATION

TYPE OF WELLS/ BORINGS TO

BE CONSTRUCTED

☒ Groundwater 3 ☐ Vadose ☐ Boring ☐ Soil Vapor ☐ Other

NUMBER OF WELLS TO BE

DESTROYED

☐ Destruction

MATERIALS TO BE USED

CASING SEAL/BORING

BACKFILL

Not Applicable ☐ Neat Cement Type PVC ☒ Cement & Bentonite Gauge3 SCH 40 ☐ Sand-Cement Diameter two (2”), one (4”)

☐ Bentonite

Screen Size 0.02 ☐ Other Filter Pack #3 Sand

Borehole diameter two (8”), one (10”)

Drilling Method ☒ Auger ☐ Air Rotary ☐ Direct Push ☐ Sonic ☐ Other ☐ Percussion

PROPOSED CONSTRUCTION

Estimated Groundwater Depth:

14 ft.

Estimated Depth of Boring:

31 ft.

Concrete Seal: 0 to 3

Annular Seal: 3 to 8

Filter Pack: 8 to 30

Perforation: 10 to 30

NOTE: Attach a well construction diagram

OFFICE USE ONLY

PERMIT LMWP# _______________

SAM CASE Y/N # ______________

DATE RECEIVED: ______________

FEE PAID: ____________________

CHECK # _____________________

EAbuyen Oval

EAbuyen Typewritten Text

ONLINE

EAbuyen Typewritten Text 10/27/2021

EAbuyen Typewritten Text N/A

EAbuyen Typewritten Text 005262

EAbuyen Typewritten Text $847

S:\LWQ\WELL PROGRAM\Monitoring Wells\Applications (Rev. 7-2019) Page 2 of 3 County of San Diego Department of Environmental Health

I agree to comply with the requirements of the current Site Assessment and Mitigation Manual, and with all ordinances and laws of the County of San Diego and the State of California pertaining to well/boring construction and destruction.

DRILLER’S SIGNATURE ____________________________________________ DATE __________________________

Within 60 days of completion, I will furnish the Monitoring Well Permit Desk (858) 505-6688 with a complete well/boring log.

I will certify the design and construction or destruction of the well/borings in accordance with the permit application.

PG/RCE/CEG SIGNATURE __________________________________________ DATE __________________________

F. SITE INFORMATION - A Property Owner Consent agreement is required for all applications, except for onsite, open LOP/SAM site assessment cases, Caltrans properties and military properties. Submit a separate sheet for additional parcels.

1. ASSESSOR’S PARCEL NUMBER Adjacent to the west of 1332020600

Site Name Cole Grade Road Bridge Project over Keys Creek

Site Address Cole Grade Road City Valley Center Zip 92082

PROPERTY OWNER County of San Diego Department of Public Works

Phone 858-694-2815 Ext. Fax

Mailing Address 5510 Overland Avenue, Suite 410 City San Diego State CA Zip 92123

NUMBER OF WELLS 3 TYPE OF WELLS Groundwater Monitoring

2. ASSESSOR’S PARCEL NUMBER

Site Address City Zip

PROPERTY OWNER

Phone Ext. Fax

Mailing Address City State Zip

NUMBER OF WELLS TYPE OF WELLS

G. QUESTIONNAIRE: Please answer all applicable questions completely and submit any required supportive documentation.

1. What is the purpose of the well/boring investigation?

☐ a. Part of an ongoing site assessment case in which a government regulator is the lead agency.

If yes, indicate which government regulator is the lead agency and the case number.

☐ Department of Environmental Health

☐ Regional Water Quality Control Board

4/29/2021

29 April 2021

S:\LWQ\WELL PROGRAM\Monitoring Wells\Applications (Rev. 7-2019) Page 3 of 3 County of San Diego Department of Environmental Health

☐ Department of Toxic Substances Control

☐ b. Part of a Phase I investigation for property ownership transfer.

☐ c. Geotechnical investigation for proposed construction or land stabilization.

☒ d. Other: Dewatering Study

2. If wells are to be destroyed, provide a description of method of destruction Following completion of the dewatering study, the wells will be abandoned by overdrilling and backfilling with bentonite/cement. Well casing and well construction materials will be removed.

3. Are you proposing a variation from current SAM Manual Requirements for the construction or destruction of borings, Vadose and/or Groundwater Monitoring Wells? If yes, specify these variations and include a well construction diagram and all required supporting documentation. Refer to the SAM Manual Appendix B for monitoring well guidelines. Yes ☐ No ☒ http://www.sandiegocounty.gov/content/dam/sdc/deh/water/docs/sam_appendix_b.pdf

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108611016 | 4/21

PROPOSED WELL LOCATIONS

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PROPOSED WELL MONITORING WELL

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EXHIBIT 3

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WELL CONSTRUCTION DIAGRAM, 2-INCH WELL

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108611016 I 4/21 Geotechnical & Environmental Sciences Consultants

T.D. 31 FEET

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#3 SAND

TRAFFIC-RATED

WELL COVER

2" DIAMETER, WATER TIGHT LOCKING WELL CAP

2" DIAMETER, SCH. 40, BLANK PVC CASING

2" DIAMETER, SCH 40,

Not to Scale

BENTONITE SEAL (BENTONITE CHIPS HYDRATED

WITH 5 GALLONS OF WATER)

0.020" SLOTTED PVC CASING

PROPOSED CONSTRUCTION

5% BENTONITE/PORTLAND CEMENT GROUT

AutoCAD SHX Text 1"-2"

AutoCAD SHX Text

30.0' BTOC

AutoCAD SHX Text

3.0' BTOC

AutoCAD SHX Text 3'

AutoCAD SHX Text

5.0' BTOC

AutoCAD SHX Text

8.0' BTOC

AutoCAD SHX Text

10.0' BTOC

AutoCAD SHX Text

31.0' BTOC

AutoCAD SHX Text

1' MINIMUM

AutoCAD SHX Text 8"

AutoCAD SHX Text 3'

WELL CONSTRUCTION DIAGRAM, 4-INCH WELL

FIGURE B-2

B2

P M

W .D

W G

A O

B

COLE GRADE ROAD BRIDGE PROJECT

VALLEY CENTER, CALIFORNIA

108611016 I 4/21 Geotechnical & Environmental Sciences Consultants

T.D. 31 FEET

CONCRETE (4000 PSI)

THREADED ON END CAP

#3 SAND

TRAFFIC-RATED

WELL COVER

4" DIAMETER, WATER TIGHT LOCKING WELL CAP

4" DIAMETER, SCH. 40, BLANK PVC CASING

4" DIAMETER, SCH 40,

Not to Scale

BENTONITE SEAL (BENTONITE CHIPS HYDRATED

WITH 5 GALLONS OF WATER)

0.020" SLOTTED PVC CASING

PROPOSED CONSTRUCTION

5% BENTONITE/PORTLAND CEMENT GROUT

AutoCAD SHX Text 1"-2"

AutoCAD SHX Text

30.0' BTOC

AutoCAD SHX Text

3.0' BTOC

AutoCAD SHX Text 3'

AutoCAD SHX Text

5.0' BTOC

AutoCAD SHX Text

8.0' BTOC

AutoCAD SHX Text

10.0' BTOC

AutoCAD SHX Text

31.0' BTOC

AutoCAD SHX Text

1' MINIMUM

AutoCAD SHX Text 10"

AutoCAD SHX Text 3'

COUNTY OF SAN DIEGO

DEPARTMENT OF PUBLIC WORKS

PRIVATE DEVELOPMENT CONST.

INSPECTION

5510 OVERLAND AVE, SUITE 210

SAN DIEGO, CALIFORNIA 92123-1239

(858) 694-3165 FAX: (858) 694-2354

ENCROACHMENT PERMIT

DATE ISSUED:

EXPIRATION DATE:

05/20/2021 04/08/2022

TRUST ACCOUNT NO.: PERMIT NO.: DPW2021-RWENCP-93239

Financial Source: Internal Agreement Number PWR-01233

APPLICANT:

NINYO & MOORE

ADRIAN OLIVARES

5710 RUFFIN RD

SAN DIEGO, CA 92123

858 576 1000

PERMIT OWNER:

NINYO & MOORE

5710 RUFFIN RD

SAN DIEGO, CA 92123

858 576 1000

AOLIVARES@NINYOANDMOORE.COM

SITE ADDRESS / JOB LOCATION:

COLE GRADE / VALLEY CENTER - TB 1070 - F3

APN: Agency Job No.: GPS COORD.:

DETAILED DESCRIPTION:

TO ENCROACH IN THE COUNTY OF SAN DIEGO RIGHT OF WAY TO: INSTALLATION, TESTING AND REMOVAL OF THREE GROUNDWATER MONITORING WELLS FOR COLE GRADE ROAD BRIDGE PROJECT OVER KEYS CREEK ORACLE PROJECT

NUMBER 1003046

Related Permits: DPW2021-RWEXCP-74236, DPW2021-RWTCP-00542, NEW DPW2021-RWTCP-01191

NOTES:

A) Stormwater Best Management Practices (BMPs) are required at all times and shall be planned and installed in accordance with the County's Watershed Protection Ordinance, Municipal Separate Storm Sewer System Permit (MS4), and, if applicable, the State Construction General Permit regulations .

B) Traffic Control Permit(s) are required and must be obtained prior to start of any work in the County's Road ROW. Hours of work may be determined by the Traffic Control Permit.

C) Existing culverts and other road facilities shall be protected in place against any damage. Any culvert or road facility and all existing paved and unpaved areas damaged, disturbed, or removed by the permitted work shall be reported immediately to DPW and be repaired to the County Standards as approved by a DPW PDCI inspector.

D) Gate Well Cap and Can installations shall meet San Diego Regional Standard Drawing WV-02.

E) Bollards are not allowed in the Right-of-Way to protect equipment per Highway Design Standards Section 2.2 No. 14. No less than an 8ft minimum clear recovery zone (CRZ) shall be maintained for roadways without curbs.

F) Subject to Streets and Highways Code Sections 732.5, 1492.5 and 1810.5; Survey monuments shall be preserved, referenced, and/or replaced pursuant to Section 8771 of the Business and Professions Code.

G) Permit owner shall comply with all applicable laws in the establishment, maintenance and removal of the encroachment.

H) Any person(s) engaged in any work authorized by this permit shall conform to all due safety precautions for the protection of persons and property.

I) Permit owner shall remove or relocate any encroachment placed, changed or renewed under the authority of this permit; prior to its expiration or within 24 hours of notification to remove, if the duration is 10 or less; or within 5 day of notification to remove, if the permit is of indefinite duration.

J) After removing or relocating an encroachment, the highway shall be restored to the equivalent or better condition than it was prior to the date this permit became effective, or prior to the date the encroachment was first placed, whichever is earlier.

PERMIT EXTENSION: 10/11/2021

JUSTIFICATION FOR ENCROACHMENT: AQUIFER TEST FOR THE DESIGN OF THE COLE GRADE ROAD BRIDGE PROJECT

OVER KEYS CREEK ORACLE PROJECT NUMBER 1003046

Encroachment Permit Page 1 of 2Permit No. DPW2021-RWENCP-93239

This permit is granted under provision of Title 7 of the San Diego County Code of Regulatory Ordinances, and is subject to the following terms:

Permit Owner agrees to indemnify, hold harmless and defend the County and each of its officers and employees from any liability or responsibility for accident, loss or damage to persons or property arising in any way from the encroachment authorized by this permit, including the design or performance of work by Permit Owner, or Permit Owner's agents, employees or representatives.

Issuance of this permit does not grant Permit Owner any property rights. Permit Owner is solely responsible for obtaining any property rights that may be necessary to conduct work under this permit.

This permit does not authorize interference with the public use and maintenance of the public highway, including without limitation, any traveled way, shoulder, parking lane, sidepath, sidewalk, landscaped areas, drainage structure or watercourse. Upon receipt of reasonable notice from the Director, Department of Public Works, Permit Owner shall relocate, change the grade, or remove the encroachment in a manner and to a location acceptable to Director.

County of San Diego, Director of Public Works by: Date:

Encroachment Permit Page 2 of 2Permit No. DPW2021-RWENCP-93239

10/11/2021

ENCROACHMENT/EXCAVATION/CONSTRUCTION PERMIT #

EXTENSION - PREVIOUS PERMIT: DPW2021-RWTCP-00542

DPW2021-RWEXCP-74236 & DPW2021-RWENCP-93239

Applicant Information

Company: NINYO & MOORE Agent/Applicant: ADRIAN OLIVARES Agent Phone Number: 858 576 1000 Agent Email Address: AOLIVARES@NINYOANDMOORE.COM Agent Mailing Address: 5710 RUFFIN RD

City: SAN DIEGO State: CA Zip Code: 92123

Reason for Traffic Control:

TO INSTALLATION, TESTING, AND REMOVAL OF THREE GROUNDWATER MONITORING

WELLS FOR THE COLE GRADE ROAD BRIGDE PROJECT OVER KEYS CREEK OPN

1003046

Start Date: 10/11/2021 Start Time: 08:30 AM

Finish Date: 04/08/2022 End Time: 04:00 PM

COMMUNITY VALLEY CENTER TB 1070 F3 Thomas Bros. Map Page and Grid #

04/16/2021 (Agent's or Applicant's Signature) (Date)

See Attached Plan (s) and Traffic Control Notes

This request is approved.

Director, Department of Public Works

By (For Road Commissioner) (Date)

County of San Diego

DEPARTMENT OF PUBLIC WORKS

TRAFFIC ENGINEERING SECTION

APPLICATION FOR TRAFFIC CONTROL PERMIT -- ATTACHED REVISED PLANS

(type of traffic control: flag, shift, etc.)

County of San Diego DPW / Traffic Engineering (MS 0332) 5510 Overland Ave, Suite 410 San Diego, CA 92123-1239 telephone/voice mail: (858) 694-3863 secretary: (858) 694-3850 fax: (858) 694-3928 e-mail:

DPWTrafficControl.permit@sdcounty.ca.gov

DPW2021-RWTCP-01191

It is requested that a permit be granted for traffic control on the following street/streets:

STREET 1 COLE GRADE RD

From Street AT COOL VALLEY RD To

CC: Construction Inspection Ref: Sec 72.75. County Code of Regulatory Ordinances

SIGNATURE ON APPLICATION

10/11/2021

Ninyo & Moore | Cole Grade Road Bridge Project Over Keys Creek, San Diego County, California | 108611016 | June 21, 2023 11

APPENDIX B

Boring Logs and Well Construction Diagram

ML

SW

SW-SM

SP-SM

FILL:

Dark brown, slightly moist to moist, very fine sandy SILT.

Brown, slightly moist, fine silty SAND; with glass and fine to coarse gravel; rootlets.

ALLUVIUM:

Yellowish brown, moist, very fine silty SAND; with rootlets.

Dark brown; micaceous; wet.

Grayish brown to gray, wet, silty SAND; with gravels.

Increased silt content; micaceous.

Silty layers; contains clay (interbedded).

Total Depth = 31.5 feet.

Well Depth = 30 feet.

Groundwater encountered at approximately 13 feet during drilling.

Groundwater monitoring well constructed on 12/07/21.

Note: Groundwater may rise to a level higher than that measured in borehole due to seasonal variations in precipitation and several other factors as discussed in the report.

The ground elevation shown above is an estimation only. It is based on our interpretations of published maps and other documents reviewed for the purposes of this evaluation. It is not sufficiently accurate for preparing construction bids and design documents.

FIGURE B- 1

COLE GRADE ROAD BRIDGE PROJECT OVER KEYS CREEK

SAN DIEGO COUNTY, CALIFORNIA

108611016 | 6/23

D E

P T

H fe et

B u lk S

A M

P

LE

S D riv e n

B L

O W

S /F

O O

T

M O

IS

T

U R

E

D R

Y D

E N

S

IT

Y

P C

F

S Y

M B

O L

C L

A S

S

IF

IC

A

T

IO

N U

.S .C

.S

DESCRIPTION/INTERPRETATION

DATE DRILLED 12/07/21 BORING NO. OW1

GROUND ELEVATION 1,435' (MSL) SHEET 1 OF

METHOD OF DRILLING 8" Diameter Hollow Stem Auger (Limited Access Rig)

DRIVE WEIGHT 140 lbs. DROP 30"

SAMPLED BY GAH LOGGED BY GAH/BAB REVIEWED BY BAB

ML

SW

SW-SM

SP-SM

FILL:

Dark brown, slightly moist, very fine sandy SILT.

Brown, slightly moist, fine silty SAND; with fine to coarse gravel.

ALLUVIUM:

Reddish brown, slightly moist, very fine, silty SAND with rootlets.

Dark brown; wet.

Grayish brown, wet, silty SAND; with gravel.

Fine grained; increase in silt; rootlets.

Silt lamination.

Increase in gravels.

Total Depth = 31.5 feet.

Well Depth = 30 feet.

Groundwater encountered at approximately 13 feet during drilling.

Groundwater monitoring well constructed on 12/08/21.

Note: Groundwater may rise to a level higher than that measured in borehole due to seasonal variations in precipitation and several other factors as discussed in the report.

The ground elevation shown above is an estimation only. It is based on our interpretations of published maps and other documents reviewed for the purposes of this evaluation. It is not sufficiently accurate for preparing construction bids and design documents.

FIGURE B- 2

COLE GRADE ROAD BRIDGE PROJECT OVER KEYS CREEK

SAN DIEGO COUNTY, CALIFORNIA

108611016 | 6/23

D E

P T

H fe et

B u lk S

A M

P

LE

S D riv e n

B L

O W

S /F

O O

T

M O

IS

T

U R

E

D R

Y D

E N

S

IT

Y

P C

F

S Y

M B

O L

C L

A S

S

IF

IC

A

T

IO

N U

.S .C

.S

DESCRIPTION/INTERPRETATION

DATE DRILLED 12/08/21 BORING NO. OW2

GROUND ELEVATION 1,435' (MSL) SHEET 1 OF

METHOD OF DRILLING 8" Diameter Hollow Stem Auger (Limited Access Rig)

DRIVE WEIGHT 140 lbs. DROP 30"

SAMPLED BY GAH/BAB LOGGED BY GAH REVIEWED BY BAB

ML

SW

SW-SM

SP-SM

FILL:

Brown, slightly moist, very fine, sandy SILT.

Brownish reddish yellow, slightly moist, very fine, silty SAND; with gravel, cobbles, and boulders up to approximately 3 inches to 12 inches in diameter; rootlets/roots.

ALLUVIUM:

Yellowish brown, moist, silty SAND; with rootlets; micaceous.

Gray to dark gray, wet, coarse grained SAND; with silt and gravels.

Increase in silt; occasional gravels.

Laminated.

Black; very stiff interbedded clay layer.

Grayish brown.

Total Depth = 31.5 feet.

Well Depth = 30 feet.

Groundwater encountered at approximately 13 feet during drilling.

Groundwater monitoring well constructed on 12/07/21.

Note: Groundwater may rise to a level higher than that measured in borehole due to seasonal variations in precipitation and several other factors as discussed in the report.

The ground elevation shown above is an estimation only. It is based on our interpretations of published maps and other documents reviewed for the purposes of this evaluation. It is not sufficiently accurate for preparing construction bids and design documents.

FIGURE B- 3

COLE GRADE ROAD BRIDGE PROJECT OVER KEYS CREEK

SAN DIEGO COUNTY, CALIFORNIA

108611016 | 6/23

D E

P T

H fe et

B u lk S

A M

P

LE

S D riv e n

B L

O W

S /F

O O

T

M O

IS

T

U R

E

D R

Y D

E N

S

IT

Y

P C

F

S Y

M B

O L

C L

A S

S

IF

IC

A

T

IO

N U

.S .C

.S

DESCRIPTION/INTERPRETATION

DATE DRILLED 12/07/21 BORING NO. TW

GROUND ELEVATION 1,435' (MSL) SHEET 1 OF

METHOD OF DRILLING 10" Diameter Hollow Stem Auger (Limited Access Rig)

DRIVE WEIGHT 140 lbs. DROP 30"

SAMPLED BY GAH/BAB LOGGED BY GAH REVIEWED BY BAB

T.D. 31.0 FEET

CONCRETE (4000 PSI)

THREADED ON END CAP

#3 SAND

TRAFFIC-RATED

WELL COVER

4" DIAMETER, WATER TIGHT LOCKING WELL CAP

4" DIAMETER, SCH. 40, BLANK PVC CASING

4" DIAMETER, SCH 40,

Not to Scale

0.020" SLOTTED PVC CASING

WELL CONSTRUCTION DIAGRAM, TEST WELL

FIGURE B-4

B4

W C

D .D

W G

A O

B

COLE GRADE ROAD BRIDGE PROJECT

VALLEY CENTER, CALIFORNIA

108611016 I | 6/23 Geotechnical & Environmental Sciences Consultants

WELL CONSTRUCTION DIAGRAM - TW

5% BENTONITE/PORTLAND CEMENT GROUT

BENTONITE SEAL (BENTONITE CHIPS HYDRATED

WITH 5 GALLONS OF WATER)

T.D. 31.0 FEET

CONCRETE (4000 PSI)

THREADED ON END CAP

#3 SAND

TRAFFIC-RATED

WELL COVER

2" DIAMETER, WATER TIGHT LOCKING WELL CAP

2" DIAMETER, SCH. 40, BLANK PVC CASING

2" DIAMETER, SCH 40,

Not to Scale

0.020" SLOTTED PVC CASING

WELL CONSTRUCTION DIAGRAM, OBSERVATION WELLS

FIGURE B-5

B5

W C

D .D

W G

A O

B

COLE GRADE ROAD BRIDGE PROJECT

VALLEY CENTER, CALIFORNIA

108611016 I | 6/23 Geotechnical & Environmental Sciences Consultants

WELL CONSTRUCTION DIAGRAM, OW1 AND OW2

5% BENTONITE/PORTLAND CEMENT GROUT

BENTONITE SEAL (BENTONITE CHIPS HYDRATED

WITH 5 GALLONS OF WATER)

Ninyo & Moore | Cole Grade Road Bridge Project Over Keys Creek, San Diego County, California | 108611016 | June 21, 2023 12

APPENDIX C

Well Development Logs

Ninyo & Moore | Cole Grade Road Bridge Project Over Keys Creek, San Diego County, California | 108611016 | June 21, 2023 13

APPENDIX D

Waste Manifest

Denise Juhasz Typewriter

SOFCOLEG/2760593

Ninyo & Moore | Cole Grade Road Bridge Project Over Keys Creek, San Diego County, California | 108611016 | June 21, 2023 14

APPENDIX E

Grain Size Analysis

SIEVE+HYDRO TW @ 10.0-30.0

Coarse Fine Coarse Medium SILT CLAY

3" 2" 1-1/2" 1" 3/4" 3/8" 4 10 30 50 200

PERFORMED IN GENERAL ACCORDANCE WITH ASTM D 422

Passing No. 200

GRAVEL SAND FINES

Symbol Plasticity Index

Plastic Limit

Fine

Sample Location

CcCu

Depth (ft)

D30D10

USCS

TW 10.0-30.0 -- -- -- 0.090 0.215 0.665 7.4

D60 Liquid Limit

0.8 8 SP-SM

0.0

10.0

20.0

30.0

40.0

50.0

60.0

70.0

80.0

90.0

100.0

0.00010.0010.010.1110100

PE

R

C

EN

T

FI

N

ER

B Y

W

EI

G H

T

GRAIN SIZE IN MILLIMETERS

U.S. STANDARD SIEVE NUMBERS HYDROMETER

GRADATION TEST RESULTS

COLE GRADE ROAD BRIDGE OVER KEYS CREEK PROJECT

SAN DIEGO COUNTY, CALIFORNIA

108611016 | 6/23

FIGURE E-1

Ninyo & Moore | Cole Grade Road Bridge Project Over Keys Creek, San Diego County, California | 108611016 | June 21, 2023 15

APPENDIX F

Laboratory Analytical Reports

EnviroMatrix Analytical, Inc.

Ninyo & Moore

Cole Grade Rd. / 108611016

San Diego, CA 92123

5710 Ruffin Road

Gabriel Haro

Enclosed are the results of analyses for samples received by the laboratory on 02/03/22 09:54. Samples were analyzed pursuant to client request utilizing EPA or other ELAP approved methodologies. I certify that this data is in compliance both technically and for completeness.

02 March 2022

Attn:

EMA Log #: 22B0081

Laboratory Director

Leland S. Pitt

CA ELAP Certification #: 2564

Project:

9590 Chesapeake Dr. - San Diego, California 92123 - (858) 560-7717 - Fax (858) 560-7763

Analytical Chemistry Laboratory

PLEASE NOTE OUR NEW LOCATION:

Project Name:

Ninyo & MooreClient Name: EMA Log #: 22B0081

Cole Grade Rd. / 108611016

Sample ID Laboratory ID Matrix Date Sampled

ANALYTICAL REPORT FOR SAMPLES

Date Received

TW 22B0081-01 02/03/22 06:51 02/03/22 09:54Grnd-Water

Keys Creek 22B0081-02 02/03/22 07:11 02/03/22 09:54Pond Water

The results in this report apply to the samples analyzed in accordance with the chain of custody document. This analytical report must be reproduced in its entirety.

Cole Grade Rd. / 108611016

Conventional Chemistry Parameters by Standard/EPA Methods

Analyte Result MDL Limit Reporting

Units Dilution Batch Sample Prepared Sample Analyzed Method Notes Analyst

Keys Creek (22B0081-02) Pond Water Sampled: 02/03/22 07:11 Received: 02/03/22 09:54

2022866 02/28/22 11:20 03/02/22 08:59 mg

CaCO3/

L

11110 10 10Hardness (Total) EPA 200.7NLF

The results in this report apply to the samples analyzed in accordance with the chain of custody document. This analytical report must be reproduced in its entirety.

Cole Grade Rd. / 108611016

Microbiological Parameters by Standard Methods

Analyte Result MDL Limit Reporting

Units Dilution Batch Sample Prepared Sample Analyzed Method Notes Analyst

TW (22B0081-01) Grnd-Water Sampled: 02/03/22 06:51 Received: 02/03/22 09:54

2020339 02/03/22 10:54 02/07/22 07:54

MPN/10

0 ml

126 2 2Total Coliforms SM 9221 B, EAZ

"02/03/22 10:54 02/06/22 08:49

" ""Fecal Coliforms ND 22 AZ

The results in this report apply to the samples analyzed in accordance with the chain of custody document. This analytical report must be reproduced in its entirety.

Cole Grade Rd. / 108611016

Result Limit

Reporting

Units Level

Spike

Result

Source

%REC

%REC

Limits RPD

RPD

Limit Notes Analyte

Conventional Chemistry Parameters by Standard/EPA Methods - Quality Control

MDL Analyst

Batch 2022866

Blank (2022866-BLK1) Prepared: 02/28/22 Analyzed: 03/02/22

Hardness (Total) mg

CaCO3/

L

10ND 10 NLF

Duplicate (2022866-DUP1) Prepared: 02/28/22 Analyzed: 03/02/22 Source: 22A0831-01

Hardness (Total) mg

CaCO3/

L

215 0.5 2010216 10 NLF

The results in this report apply to the samples analyzed in accordance with the chain of custody document. This analytical report must be reproduced in its entirety.

Cole Grade Rd. / 108611016

Notes and Definitions

Sample results reported on a dry weight basis (if indicated in units column)

Relative Percent DifferenceRPD dry

Not ReportedNR

Analyte NOT DETECTED at or above the reporting limit (or method detection limit when specified)ND

MDL Method detection limit (indicated per client's request)

The results in this report apply to the samples analyzed in accordance with the chain of custody document. This analytical report must be reproduced in its entirety.

ANALYTICAL REPORT

Eurofins Calscience 2841 Dow Avenue, Suite 100 Tustin, CA 92780 Tel: (714)895-5494

Laboratory Job ID: 570-83286-1 Client Project/Site: Cole Grade Rd NPDES Revision: 2

For:

Ninyo & Moore 5710 Ruffin Road San Diego, California 92123

Attn: Adrian Olivares

Authorized for release by:

3/9/2022 9:57:40 AM

Virendra Patel, Project Manager I (714)895-5494 Virendra.Patel@eurofinset.com

The test results in this report meet all 2003 NELAC, 2009 TNI, and 2016 TNI requirements for accredited parameters, exceptions are noted in this report. This report may not be reproduced except in full, and with written approval from the laboratory. For questions please contact the Project Manager at the e-mail address or telephone number listed on this page.

This report has been electronically signed and authorized by the signatory. Electronic signature is intended to be the legally binding equivalent of a traditionally handwritten signature.

Results relate only to the items tested and the sample(s) as received by the laboratory.

https://secure.testamericainc.com/TotalAccess/login.aspx http://www.testamericainc.com/services-we-offer/ask-the-expert http://www.eurofinsus.com/Env mailto:Virendra.Patel@eurofinset.com

Table of Contents

Client: Ninyo & Moore Project/Site: Cole Grade Rd NPDES

Laboratory Job ID: 570-83286-1

Eurofins Calscience

3/9/2022 (Rev. 2)

Cover Page

Table of Contents

Definitions/Glossary

Case Narrative

Detection Summary

Client Sample Results

Toxicity Summary

Surrogate Summary

Isotope Dilution Summary

QC Sample Results

QC Association Summary

Lab Chronicle

Certification Summary

Method Summary

Sample Summary

Chain of Custody

Receipt Checklists

Definitions/Glossary Job ID: 570-83286-1Client: Ninyo & Moore

Project/Site: Cole Grade Rd NPDES

Qualifiers

GC/MS VOA

Qualifier Description

*+ LCS and/or LCSD is outside acceptance limits, high biased.

Qualifier

F1 MS and/or MSD recovery exceeds control limits.

GC Semi VOA Qualifier Description

J Result is less than the RL but greater than or equal to the MDL and the concentration is an approximate value.

Qualifier

HPLC/IC

Qualifier Description

4 MS, MSD: The analyte present in the original sample is greater than 4 times the matrix spike concentration; therefore, control limits are not applicable.

Qualifier

F1 MS and/or MSD recovery exceeds control limits.

J Result is less than…